Electric projection screen roller structure

ABSTRACT

An electric projection screen roller structure includes a rolling shaft and an inserting piece. The rolling shaft is provided with a sliding groove in one side surface, a flanged strip and a hollow are formed adjacent to the sliding groove, and a slant inserting block is provided adjacent to the hollow. A plurality of notches and flanged portions are provided adjacent to the slant inserting block. The inserting piece is provided with a flanged block on one side, a hollow s formed in the interior, a slant hook portion is provided at one side of the hollow, and a plurality of notches and flanged portions are provided adjacent to the slant hook portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electric projection screen roller structure, the roller structure being provided in a protective housing. More particularly, the present invention is directed to a roller structure which includes a rolling shaft and an inserting piece, so as to be easily assembled and firmly secure one end section of a projection screen, for the projection screen to smoothly unwind from the roller structure to descend below or wind around the roller structure to a raised, storage position.

2 Description of the Related Art

Various activities to pass on knowledge and information are frequently held in modern times. Projectors are widely used as auxiliary teaching tools in most teaching activities. Accordingly, a projection screen is indispensable for showing the projected content from the a projector.

While being used, referring to FIGS. 1,2 and 3, an electric projection screen housing 10 containing a scroll of projection screen 20 must be secured to a wall first, and the projection screen 20 together with a weight-balance rod 50 unwinds from a roller 30 to descend below the housing 10 to a lowered, viewing arrangement depending on the rotation of the roller 30 performed by an electrically powered motor.

A conventional projection screen roller 30 does not be provided with any structure for securing one end section of the projection screen 20, but a piece of tape 40 is adhered on a predetermined surface position of the roller 30 for ene end section of the projection screen 20 to be secured thereto. Although it can secure one end section of the projection screen 20 to the surface position of the roller 30 by the tape 40, there are the following drawbacks in the structure of the conventional projection screen roller after being used for a period of time

1. The tape 40 adhered on the surface of the roller 30 will lose stickiness after contacting with the projection screen 20 for a period of time, so that the end section of the projection screen 20 will easily separate from the roller 30.

2. Because of the changes of temperatures, the tape 40 adhered on the surface of the roller 30 will lose stickiness after being used for a period of time, so that the end section of the projection screen 20 will easily separate from the roller 30.

SUMMARY OF THE INVENTION

Therefore, the present invention is designed to provide an electric projection screen roller structure that substantially obviates the drawbacks of the related conventional art.

An object of the present invention is to provide an electric projection screen roller which can be easily assembled or disassembled.

Another object of the present invention is to provide an electric projection screen roller structure which can firmly secure one end section of a projection screen to prevent from separation after being used for a long time, so as to prolong the service life of the projection screen and the roller structure.

To achieve these advantages, the present invention provides an electric projection screen roller structure. The roller structure includes a rolling shaft and an inserting piece. The rolling shaft is provided with a sliding groove in one side surface, a flanged strip and a hollow are formed adjacent to the sliding groove, and a slant inserting block is provided adjacent to the hollow. A plurality of notches and flanged portions are provided adjacent to the slant inserting block. The inserting piece is provided with a flanged block on one side, a hollow is formed in the interior, a slant hook portion is provided at one side of the hollow, and a plurality of notches and flanged portions are provided adjacent to the slant hook portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, in which

FIG. 1 is a front view of a conventional electric projection screen roller placed in a protective housing and a projection screen unwinding from the roller to a viewing arrangement;

FIG. 2 is a perspective schematic view of the conventional electric projection screen roller placed in a protective housing and a projection screen unwinding from the roller to descend below the housing arrangement;

FIG. 3 is a cross-sectional schematic view of the conventional electric projection screen roller placed in a protective housing and a projection screen unwinding from the roller to descend below the housing to a viewing arrangement or winding around the roller to a raised position;

FIG. 4 is a perspective exploded view of an embodiment of the electric projection screen roller structure in accordance with the present invention;

FIG. 5 is a cross-sectional schematic view of an embodiment of the electric projection screen roller structure while being assembled in accordance with the present invention;

FIG. 6 is a cross-sectional schematic view of an embodiment of the electric projection screen roller structure in assembled configuration in accordance with the present invention; and,

FIG. 7 is a cross-sectional schematic view of an embodiment of the electric projection screen roller structure placed in a protective housing and a projection screen unwinding from the roller structure to descend below the housing to a viewing arrangement or winding around the roller structure to a raised position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 4, a preferred embodiment of the present invention provides an electric projection screen roller structure. The roller structure includes a rolling shaft 1 and an inserting piece 2. The rolling shaft 1 is provided with a sliding groove 11 in one predetermined side surface, a flanged strip 12 and a hollow 13 are formed adjacent to the sliding groove 11, and a slant inserting block 14 is provided adjacent to the hollow 13. A plurality of notches 15 and flanged portions 16 are provided adjacent to the slant inserting block 14.

The inserting piece 2 is provided with a flanged block 21 on one end, a hollow 22 is formed in the interior, a slant hook portion 23 is provided at one side of the hollow 22, and a plurality of flanged portions 24 and notches 25 are provided adjacent to the slant hook portion 23.

Referring to FIGS. 5,6 and 7, while being assembled, the flanged block 21 of the inserting piece 2 is inserted into the sliding groove 11 of the roller shaft 1, for the roller shaft 1 to be assembled with the inserting piece 2, one end section of a projection screen 3 is placed on the flanged portions 16 of the roller shaft 1, then the inserting piece 2 is pressed down to force the slant hook portion 23 to be inlaid in the slant inserting block 14, the flanged portions 24, 16 of the inserting piece 2 and the roller shaft 1 are respectively inlaid in the notches 15,25 of the inserting piece 2 and the roller shaft 1 at the same time, and the inserting piece 2 and the roller shaft 1 are firmly assembled together to secure one end section of the projection screen 3. In order to separate one end section of the projection screen 3 from the roller structure, the inserting piece 2 is pulled away from the roller shaft 1 to a certain distance, and then the flanged portions 24, 16 of the inserting piece 2 and the roller shaft 1 are respectively moved to separate from the notches 15,25 of the inserting piece 2 and the roller shaft 1 so as to release one end section of the projection screen 3.

While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made thereto and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention. 

1. An electric projection screen roller structure comprising: a rolling shaft being provided with a sliding groove in one predetermined side surface, a flanged strip and a hollow being formed adjacent to said sliding groove, a slant inserting block being provided adjacent to said hollow of said rolling shaft, notches and flanged portions being provided adjacent to said slant inserting block; and, an inserting piece being provided with a flanged block on one end, a hollow being formed in the interior of said inserting piece, a slant hook portion being provided at one side of said hollow of said inserting piece, flanged portions and notches are provided adjacent to said slant ook portion. 